• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2307-2314
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• 2008

The study that automates the variety of equipment using the USN(Ubiquitous Sensor Networks) has been executed, and the research field is ranged to almost all fields including a road, harbors. building, military affairs, agriculture and home. By deploying these sensors into the greenhouse environment, we can monitor the environmental change and the growth of plants 24 hours a day. However, the limited resources of a sensor node like limited energy, short transmission range etc, make it difficult to expand the size of the sensor networks. In this paper, we studied to expand the site of sensor networks by using WMN(Wireless Mesh Networks) with simulation. With this simulation, we could validate that using the Wireless Mesh Networks technology for expanding sensor networks is more efficient in the energy aspect than the normal sensor network.

• Journal of the Korean Solar Energy Society
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• v.27 no.3
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• pp.15-21
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• 2007

The purpose of this study is to provide the basic data for passive control and energy conservation strategies of multipurpose greenhouse. Passive design strategies which are appropriate to Jeju environmental circumstance were applied in the multipurpose greenhouse. The field measurement were conducted to examine relationship of micro climate and indoor thermal environment in the multipurpose greenhouse. The result of this study can be summarized as follow ; (1) The indoor temperature was ranged from 5 to $21^{\circ}C$ without a heating system, when the exterior temperature was -1 to $19^{\circ}C$. (2) The multi-purpose greenhouse requires almost no heating energy in winter, when it is used as a greenhouse, an exhibition hall or a cafeteria.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2000.11a
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• pp.233-236
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• 2000

산업발달과 더불어 급속한 속도로 오염되고 있는 환경문제는 날로 두드려져 그린하우스 효과, 산성비 등의 출현과 더불어 세계 곳곳의 기후이변을 야기하였다. 그 원인은 지구상에서 빠른 산업화 및 과학화로 인하여 화석연료의 과다사용과 그 매연으로 인한 지구환경의 불균형을 초래하였기 때문이며, 지구온난화는 그 좋은 예라고 할 수 있다. 따라서 지구환경 보전문제로서 새로운 유독성 오염물질의 처리기술이 요구되며 에너지 고갈을 대비한 비에너지 소비성 분해기술의 확보가 시급한 실정이다. 그러므로 태양에너지와 같은 무공해 에너지원을 driving force 로 활용하여 유독성 오염물질을 상온에서 완전 분해하여 전혀 무해한 물질로 분해하는 시스템의 개발은 필수적이다.(중략)

• Journal of Biosystems Engineering
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• v.23 no.2
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• pp.147-156
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• 1998

It is desirable to use the renewable energy for the greenhouse heating in winter season, it make possible not only to save fossil fuel and conserve green environment but also to promote the quality of agricultural products and reduce the agricultural production cost. In this study the heat pump - PCM latent heat storage system has been developed to use the natural energy as much as possible for the thermal environment control of greenhouse. The coefficient of performance (COP) of the heat pump system was 3~4 with the ambient temperature ranging from 8$^{\circ}C$ to -8$^{\circ}C$, and greenhouse heating effect of the heat pump-PCM latent heat storage system on the basis of the ambient temperature was about 12-15$^{\circ}C$.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.3
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• pp.113-124
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• 2009

This study has attempted to calculate the intensity of illumination for the optimal growth environment of indoor plants after analyzing both damage to plant species and growth conditions as impacted by light conditions for the Kyobo Life Insurance greenhouse. The optical intensity of illumination has been estimated after investigating the problems of growth conditions based on an analysis of illumination by light condition, dead tree replacement cycle(weeks) and rate of damage of plant species. According to the investigation of illumination, the lowest difference was observed between the shaded spot in the south(531lux) and the sunny spot(602lux) while the largest difference(nearly 500lux) was detected between the shaded spot in the central area(210lux) and the sunny spot(782lux). According to an analysis of dead trees from 1990 to 2004, in terms of dead tree replacement cycle, Viburnum awabuki was the highest(161weeks), followed by Phyllostachys spp.(84weeks), Camellia japonica and Ternstroemia japonica(40weeks). Regardless of plant species, damage rate of plant were lower in the shaded spot and higher in the sunny spot. According to correlation and regression analyses with the intensity of illumination as an independent variable and the damage rate of plant species as a dependent variable, the damage rate of plant species increased as the intensity of illumination decreased. A dramatic decline in the rate of damage was observed at $500{\sim}600lux$. At 700lux, it reached the lowest level.

• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.155-162
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• 2001

The greenhouse heating system with heat pump was built for development of simulation model and validation. The computer simulation model for the system to predict temperature of air and soil and moisture content of soil in the greenhouse were developed, and its validity was justified by actual data. From the analysis of experimentally measured data and the simulation output, following results were obtained. 1. The expected values of inside air temperature for the heating system with heat pump were very much close to the experimental values. 2. In the heating system with heat pump, the expected values of day time surface temperature of soil by computer simulation were very much similar to the measured values, but those of night time were higher than the measured value by at most 2.0$\^{C}$. 3. The simulation model predicted temperature of greenhouse film as of 1$\^{C}$ below than the mean value of ambient air and greenhouse air temperature. 4. Heat loss value of daytime was found to be larger than that of nigh as much as 1.3 to 2.3 times for the heating system with heat pump. 5. In the heating system with heat pump, when the lowest ambient temperature was -8$\^{C}$∼-7$\^{C}$ the air temperature of greenhouse was 5$\^{C}$∼6$\^{C}$, thus the heat pump heating system contributed in greenhouse heating by 13$\^{C}$.

• Journal of Biosystems Engineering
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• v.21 no.1
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• pp.84-93
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• 1996

Several paraffins(CnH2n +2) can be used as the thermal energy storage medium because of their large amount of latent heat and their flexibility of phase change temperature. But they have not been used in the thermal energy storage system because their long term stability have not been verified. Paraffins(CnH2n+2) which the values of n are 23, 24, 26 and 28 were selected for this experimental research. And this research was peformed to apply them to the practical systems. The results were summarized as follows. (1) The increase of phase change cycles had no effect on their phase change temperatures. (2) According as the values of n increased from 23 to 28, the specific heats of paraffins(CnH2n+2) increased, and were in the range of 0.47 0.75 ㎉/$kg^circ C$. (3) Thermal conductivities of them were in the range of 0.14 0.17 W/$m^circ C$. and specific gravities of them were in the range of 765800 kg/m3. (4) The density of paraffins was in the range of 765 800 kg/$m^circ C$ , and the density of solid phase was larger than that of liquid phase. (5) When the number of phase change cycles was 1, 500 cycles, the latent heat of paraffins was 90% of the initial value.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.72-78
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• 2009

The regulation for $CO_2$ emissions from vehicles have become much more stringent in recent years. These more stringent regulations request vehicle manufacturers to develop alternative fuels to reduce exhaust emissions. In this paper, $CO_2$ emission of gasoline, diesel and LPG vehicles in the CVS-75mode is analyzed. The experimental results indicated that the cold starting acceleration period of $CO_2$ emission was much longer compared to the hot start acceleration period. For example, gasoline vehicle and LPG fuel vehicle had 21% higher $CO_2$ emission and diesel vehicle had 34% higher $CO_2$ emission.

• Journal of the Korean Solar Energy Society
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• v.21 no.2
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• pp.27-34
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• 2001

The greenhouse heating system using solar energy has been realized in the protective agriculture in this study in order to analyse the thermal energy characteristics of the system the effects of ambient air temperature, solar radiation, relative humidities and water content of ambient air on the greenhouse air temperature were investigated through computer simulation experimental analysis for validation of the simulation. The results from this study are summarized as follows: 1) The expected values of inside air temperature for the system solar energy were very much close to the experimental values. 2) In the system using solar energy, the expected values of daytime surface temperature of soil by computer simulation were very much similar to the measured values, but those of nighttime were higher than the measured value by almost $2.5^{\circ}C$. 3) Heat loss of daytime was found to be larger than that of night time as much as 2.0 to 4.2 times for the system using solar energy. 4) In the system using solar energy. while the ambient air temperature varied between $-7^{\circ}C$ and $-3.8^{\circ}C$, the temperature of the inside air was maintained between $0^{\circ}C$ and $22^{\circ}C$. 5) At the minimum ambient temperature of $-7^{\circ}C$, the temperature of the inside air was $0^{\circ}C$.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.339-345
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• 2021

'Gondalbi' (Ligularia stenocephala (Maxim.) Matsum. & Koidz.) is the most cultivated Gomchwi species because of higher yield and low in aromatic flavor and bitter taste, But 'Gondalbi' is susceptible to powdery mildew disease and leaf shriveling after harvest in Summer. To improve powdery mildew disease resistance and post-harvest leaf shriveling problem in 'Gondalbi', 'Handeari-gomchwi' resistant to powdery mildew disease and having higher yield potential used as a paternal trait donor. Powdery mildew disease resistance and post-harvest leaf shriveling as well as agronomic performance of a new variety, 'Greenbear' were tested under field and green house conditions in Pyungchang, Korea from 2007 to 2016. Expression of both maternal and paternal characteristics in 'Greenbear' including purple colored petiole ears, glossy leaf and paternal, petiole trichome, absent at the back of a leaf were confirmed. Plant size and flowering time of 'Greenbear' were similar to check line, 'Gommany', while leaf number per plant and yield were higher in 'Greenbear'. 'Greenbear' has thinner leaves (0.66mm) compared to 'Gommany (0.69 mm)', and hardness appeared slightly higher in 'Greenbear(25.1 kg/cm²)'. The resistance to powdery mildew disease of the 'Greenbear' variety was slightly lower than that of the 'Gommany' variety, but somewhat showed high resistance.